Coordination may be legal but shows how twisted campaign financing is.

He hasn’t been found guilty of doing anything illegal. He hasn’t been charged with doing anything illegal.

The documents that were released and were part of the John Doe investigation into whether Walker’s campaign in the 2011 and 2012 recall elections illegally coordinated activities with outside special-interest groups only detailed what was being investigated and what was discovered.

They didn’t reveal an ultimate conclusion of the investigation because the investigation was halted by a federal judge. It remains halted while that decision is being appealed.

The documents do, however, reveal a inside look at how at least this campaign — and others, too? — operate. It’s not a pretty picture.

The most revealing piece of information is an excerpt from an email that Walker wrote to national Republican political consultant Karl Rove in May 2011, telling Rove that R.J. Johnson, a Walker campaign strategist who also operated the special-interest organization Wisconsin Club for Growth, was operating the recall campaigns.

“Bottom-line: R.J. helps keep in place a team that is wildly successful in Wisconsin. We are running 9 recall elections and it will be like 9 congressional markets in every market in the state (and Twin Cities),” Walker wrote.

The federal judge who stopped the investigation, Rudolph Randa, said that, while state law prohibits candidates’ campaigns from coordinating with outside groups that run ads that advocate for voting for or against a candidate, coordination is OK if the outside groups run “issue” ads. They’re ads that don’t say, “Vote against Candidate X.” Instead, they say, “Tell Candidate X ...”

He said that Wisconsin Club for Growth “found a way to circumvent campaign finance laws.” A state judge overseeing the investigation made a similar ruling.

If that seems like a matter of semantics than anything else, that’s right.

How often do you see “issue” ads that aren’t related to a candidate for office? How often do you see them outside of a campaign period?

You might also ask if this all matters? It does. Candidates’ campaigns have limits on the size of individual donations they can receive and rules that require those donors’ names be made public. Special-interest groups don’t have those limits or rules. That’s why Randa said it was “a way to circumvent campaign finance laws.”

The concept is legal. Other judges will determine if the John Doe investigation will continue. But this is certainly nothing to celebrate.

It’s an ugly part of our campaign system. It’s exploiting a loophole in the law.

While it’s not illegal, it violates the spirit of the philosophy behind the law — that candidates’ campaigns should be separate from the outside groups trying to influence them so they aren’t corrupted and so they act in the interests of all of their constituents.

So, while Walker’s email to Rove may be perfectly innocent under the law, the public has a right to be concerned about it.